The subject invention is directed toward the packaging art and, more particularly, to a method and apparatus for applying a protective cap on the nozzle end of a caulking tube while substantially simultaneously therewith rolling a bead on the piston end of the tube.
In commonly assigned patent application Ser. No. 549,811, filed Feb. 14, 1975, and now U.S. Pat. No. 3,930,599 there is disclosed a protective cap adapted to be snapped into position on the nozzle end of a caulking cartridge. The cap is designed to seal the nozzle after the nozzle has been cut and a portion of the caulking compound used. In order to assure that the cap provides a good seal and is not easily dislodged during shipping or handling, it must have a relatively tight, snap-on fit with the tube.
The tight fit required of the cap presents some problems during manufacture. Although the caps are designed to be removed and applied manually, this is not economically practical during high volume manufacturing runs.
The subject inventor has developed a method and apparatus by which a protective cap of the general type described can be readily applied or installed at substantially the same time as another step of the tube manufacturing sequence is carried out. In particular, the tubes which constitute the body of the cartridge are generally formed of paperboard. Normally, during manufacture, a flange ring is placed in the piston end of the tube. The flange portion of the ring is then rolled over the end edge of the tube to form a protective and/or reinforcing bead.